It is conventional to inject subcutaneous oil-base vaccine into an adult chicken by pulling away the relatively loose flesh around the neck and using an injection needle to pierce the pulled-away skin and inject the vaccine into the cavity between the pulled-away skin and the underlying solid tissue. Hand-held injectors have been used for this purpose, but serious problems have been encountered. One is the difficulty in controlling the operation of the needle due to its discharge end being close to the operator's fingers but concealed by the bird's feathers. The result that sometimes the operator does not realize that the needle has not pierced the bird's skin before activating ejection from the needle. This causes the bird not to receive the intended injection and also wastes expensive vaccine. Another serious problem is risk of injury if one of the operator's fingers gets in the path of the needle advancing toward the bird's skin. If the vaccine enters a finger, amputation may be necessary, depending on the amount and kind of vaccine injected. Even when the bird's skin is pierced successfully, there still remains the risk of also causing the needle to stab into the neck, which usually injures the bird.